Enzymes lower the activation energy necessary to transform a reactant into a product. On the left is a reaction that is not catalyzed by an enzyme (red), and on the right is one that is (green).

Catalysis is the chemical reaction brought about by a catalyst ... Others are protein molecules, called enzymes, that are contained in microorganisms. Still others are naturally occurring solids, such ...

As with many chemical reactions, the rate of an enzyme-catalysed reaction increases as the temperature increases. However, at high temperatures the rate decreases again because the enzyme becomes ...